What is the theme of "The Lady, or the Tiger"?

There is the theme of love, that is, the confusing nature of love. The princess falls in love with a handsome young man.

". . . and she loved him with an ardor that had enough of barbarism in it to make it exceedingly warm and strong".

The theme of determination and free will; the semi-barbaric king allowed the prisoners who were subjected to his judgment to choose their fates. No one was allowed to interfere with the prisoners’ choice of the door.

The theme of civilisation and barbarity is also evident in this short story. The king is termed as semi-barbaric. “In the very olden time there lived a semi-barbaric king”. Also the princess is said to be barbaric.

“The girl was lovely, but she had dared to raise her eyes to the loved one of the princess; and, with all the intensity of the savage blood transmitted to her through long lines of wholly barbaric ancestor. . .”